Update API spec, fix some spec-related java client issues

[swallez]

Update generated code from the API specification. This includes elastic/elasticsearch-specification#1783 that fixes #318, fixes #214.

[github-actions]

The backport to 7.17 failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-7.17 7.17
# Navigate to the new working tree
cd .worktrees/backport-7.17
# Create a new branch
git switch --create backport-348-to-7.17
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick --mainline 1 272286e048a3f90a1bbcc43ea43ee79edb84ef46
# Push it to GitHub
git push --set-upstream origin backport-348-to-7.17
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-7.17

Then, create a pull request where the base branch is 7.17 and the compare/head branch is backport-348-to-7.17.

[github-actions]

The backport to 8.3 failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-8.3 8.3
# Navigate to the new working tree
cd .worktrees/backport-8.3
# Create a new branch
git switch --create backport-348-to-8.3
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick --mainline 1 272286e048a3f90a1bbcc43ea43ee79edb84ef46
# Push it to GitHub
git push --set-upstream origin backport-348-to-8.3
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-8.3

Then, create a pull request where the base branch is 8.3 and the compare/head branch is backport-348-to-8.3.